Prolonged Sitting – We All Do It But Have to Stop!

Think of how many activities you do surrounding work that involve sitting. Your list could include any or most of the following:

  • morning coffee at home
  • commuting to and from work
  • eating breakfast and dinner
  • lunch plus breaks
  • working at your computer
  • meetings with the boss/colleagues /new clients
  • reading
  • talking on the phone
  • attending a conference

For most people, very few activities do not involve sitting at work. And this is actually quite alarming because now health experts are finding that sitting is the newest disease and is even thought to be “the new smoking” bad habit.

The sitting disease is a term researchers use. They’re saying that its #1 symptom is metabolic syndrome. This is a cluster of different health conditions that includes having an extra spare tire around the middle, high blood pressure, high levels of blood sugar, high cholesterol levels and high triglycerides. These contribute to insulin resistance and can lead to Type 2 diabetes.

Our whole culture is dependent on sitting but this habit has a big issue with it: Those who sit for several hours during the day have 94% higher risk of dying an early death, and it’s a risk that’s higher than all other causes of mortality.

Sitting increases your chance of dying? How and why? And exactly how much – and should you be concerned?

Parameters of Prolonged Sitting Risks

In a 2018 medical study that appeared in the American Journal of Epidemiology, researchers followed the survey data of 127,554 people over 21 years. At the end of the follow-up, 38 percent of them had died. Those who had been sitting six or more hours a day had a greater risk of dying than the risk of dying from any of these diseases:

  • Coronary heart disease
  • Cancer
  • Diabetes • kidney disease
  • Suicide
  • COPD
  • Pneumonitis from solids/liquids
  • Liver disease
  • Other digestive diseases
  • Parkinson’s disease
  • Alzheimer’s disease
  • Nervous disorders
  • Musculoskeletal disorders

The sweet spot was less than 3 hours a day of sitting. At less than 3 hours a day, the risk of dying faded away.

The question is this – could you do it? Could you change your schedule and only sit three hours a day? Or could you somehow break up your day to prevent an early death?

What Is It About Prolonged Sitting That Harms the Body?

In another study, doctors at the Indiana University School of Medicine wanted to see what the actual effect of sitting for three hours was on the body. They were testing the relationship between three things: endothelial function of the arteries, cardiovascular disease, and sitting.

There have been reports in the medical literature that sitting disrupts endothelial function. The term “endothelial dysfunction” means the availability of the vasodilator called nitric oxide is lessened in the arteries. The purpose of nitric oxide is to keep the arteries open. When it’s in low amounts, there’s a change in the character of the arterial wall and it’s not able to dilate or open as wide as it should.

Endothelial dysfunction is a key early step for hardening of the arteries. In the early stages, there’s inflammation within the arteries. The plaque within the arteries starts to grow and then it makes it easy for blood clots to form.

How Can Endothelial Function Be Preserved During Prolonged Siting?

The researchers at the Department of Kinesiology at Indiana University tested 12 healthy men in their mid 20s for the endothelial function of the femoral artery, the artery that feeds the legs. The men sat on a chair with a very firm cushion for three hours and were not allowed to move their legs in any way. Measurements were taken to determine the dilation of the artery.

Then at another completely different time during the study, the healthy men were asked to sit on the same chair. This time they walked on a treadmill for 5 minutes at 2 miles per hour at specific points in time: after 30 minutes, 60 more minutes and 60 additional minutes. Similarly, measurements were taken to determine the dilation of the artery.

The researchers found that there was a significant decline in dilation of the artery when the men sat on the chair and couldn’t move. Sitting also affected the shear rate, or the change in velocity at which the blood was passing between the artery walls. It’s the rate at which blood is sheared or “worked” during blood flow. Sitting without moving decreased the shear rate as well.

But when the men were able to walk on the treadmill, this totally prevented the dilation of the artery.

The scientists concluded that light activity breaks could prevent the endothelial dysfunction from occurring.

Prolonged Sitting Study Has Distinct Significance for Us

This is good news for all of us! Think about it. What this research is telling us is that when we sit at a desk and rarely move for hours at a time, it’s harming our blood vessels.

The scientists in this study only tested what was happening in the femoral artery closest to the skin, not any other blood vessels. It’s entirely possible that sitting is harming the endothelial function in all the blood vessels of the body, not only the femoral artery. When nitric oxide levels decrease, then they can’t possibly be selecting only one artery in the body at a time. There has to be a global body change where all the arteries are affected.

When someone has hardening of the arteries, it can occur in the legs. Then it’s called peripheral artery disease. It can happen in the coronary artery that feeds the heart. It can also happen in the carotid artery in the neck. This artery feeds the head and brain.

If there’s a clot that dislodges from the hardened arteries in the legs, the clot will travel up to the lungs or continue on to anywhere else in the body. If there’s a clot that occurs in the coronary artery, it will cause a heart attack. And if a clot dislodges from the carotid artery, it will go to the brain and cause a stroke.

But now we know that moving every 30 to 60 minutes is the solution to getting back our endothelial function in the arteries. We must keep moving!

Stay tuned for solutions… one of them is a special task chair that can prevent the sitting disease. It’s from the ActiveSeat Company, a company dedicated to wipe out the sitting disease – and allow you to improve your productivity at work. More soon…


Thosar, S.S., et al. Effect of prolonged sitting and breaks in sitting time on endothelial function. Med Sci Sports Exerc 2015 Apr;47(4):843-9.

Patel, A.V., et al. Prolonged leisure-time spent sitting in relation to cause-specific mortality in a large U.S. cohort. Am J Epidemiol 2018 Jun 26. Epub ahead of print.